This story relates to the principles and habit of self discipline in multiple ways.
1. She wakes up at 6 AM and walks and hour to school and back, demonstrating that she has the self discipline to do these things to get a good education.
2. She supports her mother in bookbinding, and gives tuition to students, showing kindness and empathy, which is important to self discipline.
3. Despite hardships she has been grateful for whatever she has.
4. She envisions becoming an electrical engineer to support he entire village.
These examples and more show how this young woman displays self discipline.
I hope this helped.